ES2949562T3 - Stabilized chlorinated polyvinylchloride and article made from it - Google Patents

Abstract

The invention relates to a halogenated resin comprising chlorinated polyvinyl chloride (CPVC) and a stabilizing composition comprising disodium adipate in an amount greater than 0.3 parts by weight per 100 parts of polymer (phr) and in which the resin Halogenated does not include tin stabilizers. A chlorinated polyvinyl chloride article made of halogenated resin, wherein the article has a Congo red stability >= 53 min, a VICAT softening temperature > 82°C and wherein the halogenated resin formulation has a fusion <= 78 seconds. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Stabilized chlorinated polyvinylchloride and article made from it

FIELD OF THE INVENTION

[0001] The invention relates to a stabilized chlorinated polyvinylchloride (CPVC) which also has a suitable short melting time. Stabilized CPVC can be obtained through the use of a stabilizing composition comprising disodium adipate in suitable amounts and in the absence of stannous and stenic stabilizers.

STATE OF THE TECHNIQUE

[0002] Chlorinated polyvinyl chloride (CPVC) is becoming increasingly important in the industry given its superior mechanical properties compared to PVC (Journal of Vinyl and Additive Technology 1986, 8(4), 146-150). Specifically, PVC has a higher VICAT softening temperature than PVC.

[0003] Halogen-containing polymers must be subjected to temperatures more or less within the wide range of about 190 ° C in order to be worked with by known processes, such as molding, calendering and extrusion.

[0004] It is well known that halogen-containing polymers tend to degrade at the aforementioned processing temperatures due to the inherent degradation temperature of the halogenated polymers themselves, which at said temperatures release hydrochloric acid with the formation of double bonds.

[0005] These phenomena of alteration of the structure of chlorinated polymers manifest themselves in a deterioration of the mechanical properties and a darkening effect in the color. This deterioration problem is aggravated when the residence time at higher temperatures during work is longer.

[0006] Traditionally, tin stabilizers are used as CPVC stabilizers, but they are known to be toxic and it is desirable to remove them from stabilizing compositions for halogenated polymers.

[0007] Furthermore, currently known CPVC stabilizers provide limited thermal stability.

[0008] US 2017/0029593 describes a molding resin composition that includes a chlorinated vinyl chloride, a heat stabilizer, a polyalcohol and/or a partial ester of a polyalcohol. The stabilizing composition for CPVC is proposed with the objective of avoiding the use of metallic stabilizers, specifically tin stabilizers. The thermal stabilizer described herein contains at least one of a compound represented by the formula Ca-i_xZnx(OH) ² , where x meets the inequality 0<x<1 and a compound represented by the formula Ca-i.yZnyO , where y fulfills the inequality 0<y<1.

[0009] EP2083044 proposes a stabilizing composition for halogen-containing polymers comprising disodium adipate and at least one compound selected from the group consisting of metal trifluorosulfates and perchlorates. In example 4, the C-PVC stabilizer is suggested, but the final stabilizer composition still contains tin-derived stabilizers to ensure good Congo red (CR) stabilities with low yellowing rates.

[0010] Furthermore, in the case of CPVC, it is also desirable to have a suitably short melting time in processing (such as, for example, in an extruder) to obtain good quality articles.

[0011] Therefore, there is still a need to achieve a stabilizing composition, which guarantees good stabilizing effects in the absence of tin stabilizers and which is capable of providing a suitably short melting time in processing to obtain articles of good quality.

SUMMARY OF THE INVENTION

[0012] The present inventors surprisingly discovered that disodium adipate used in a specific amount can efficiently stabilize chlorinated polyvinylchloride and also with a short thermal fusion time, when used in a stabilizing composition that does not contain tin stabilizers.

[0013] Therefore, in a first aspect, the invention relates to a halogenated resin as defined in claim 1.

[0014] The halogenated resin of the invention can be in a rigid, semi-rigid and plasticizing formulation.

[0015] When the following terms are used in the present invention:

- "halogenated resin in plasticizer formulation" or "halogenated resin in semi-rigid formulation" refers to a resin comprising chlorinated polyvinylchloride formulated with a certain amount of plasticizer compounds;

- "halogenated resin in rigid formulation" refers to a resin formulation that comprises chlorinated polyvinylchloride and is substantially free of plasticizing compounds.

[0016] Unexpectedly, the specific amount of disodium adipate was found to have a surprising stabilizing effect when formulated with CPVC relative to PVC, even in the absence of tin stabilizers.

Surprisingly, the CPVC resin formulation of the invention showed a short melting time, thus allowing better workability of the resin itself.

[0017] The present inventors also surprisingly discovered that disodium adipate stabilizes chlorinated polyvinylchloride to a particularly efficient extent if it has a fine particle size. Since disodium adipate is particularly useful in solid form, providing easier handling, the particle size of disodium adipate is of peculiar technical importance.

[0018] In another aspect, the invention relates to the use as defined in claim 7.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Accordingly, the invention relates to a halogenated resin as defined in claim 1.

[0020] The disodium adipate salt of the CPVC resin stabilizer composition is present in an amount greater than 0.3 parts by weight per 100 parts of polymer (phr), preferably 0.35 to 1.6, even more preferably equal to 0.9 parts by weight per 100 parts by weight of CPVC.

[0021] The disodium adipate of the stabilizing composition shows a particle size distribution showing a D90 value of less than 8.0 microns, a D50 value of less than 1.8 microns, and a D10 value of less than 0.6 microns.

[0022] The present inventors also surprisingly discovered that disodium adipate stabilizes chlorinated polyvinylchloride to a particularly efficient extent if it has a fine particle size. Since disodium adipate is particularly useful in solid form, providing easier handling, the particle size of the disodium adipate is of peculiar importance.

[0023] The stabilizing composition comprised in the resin formulation of the invention may also comprise one or more stabilizers and co-stabilizers other than a tin stabilizer. Optional stabilizers or co-stabilizers can be selected from the group consisting of metal soaps, perchlorates and perfluoroalkanesulfonates, monosodium adipate, antioxidants, alkanolamines, zeolites and hydrotalcites, polyols, organic phosphites, p-aminocrotonic acid esters and organic co-stabilizers, such as dihydropyridines, polydihydropyridines and uracil derivatives.

[0024] The optional stabilizer is preferably comprised in the stabilizer composition in an amount in the range of 0.05 to 4 parts by weight per 100 parts of CPVC.

[0025] The following may be cited as non-limiting examples of stabilizers:

Metallic soaps

[0026] All metal soaps known for use as polyvinylchloride (PVC) stabilizers are suitable for the invention. These are preferably organic sodium, lithium, potassium, calcium, zinc, magnesium and aluminum salts of saturated C2-C22 aliphatic carboxylates, unsaturated C2-C22 aliphatic carboxylates, saturated C2-C22 aliphatic carboxylates substituted with at least one OH group, or whose chain is interrupted by at least one oxygen atom (oxyacids), cyclic or bicyclic carboxylates containing between 5 and 22 carbon atoms, phenylcarboxylates, unsubstituted or substituted with at least one OH group and/or substituted with C1-C16 alkyl, naphthylcarboxylates, unsubstituted or substituted with at least one OH group and/or substituted with C1-C16 alkyl, phenyl-(C1-C16)alkylcarboxylates, naphthyl-(C1-C16)alkylcarboxylates, or phenolates, unsubstituted or substituted with C1 alkyl -C12.

[0027] Among these, the following can be mentioned: metal salts of monovalent carboxylic acids, such as acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, n-heptanoic acid, octanoic acid, neodecanoic acid, 2-ethylhexanoic acid , nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, myristic acid, palmitic acid, lauric acid, isostearic acid, stearic acid, 12-hydroxystearic acid, 9,10-dihydroxystearic acid, oleic acid, 3,6 acid -dioxaheptanoic acid, 3,6,9-trioxadecanoic acid, behenic acid, benzoic acid, p-tert-butylbenzoic acid, dimethylhydroxybenzoic acid, 3,5-di-tert-butyl4-hydroxybenzoic acid, toluic acid (methylbenzoic), dimethylbenzoic acid, ethylbenzoic acid, n-propylbenzoic acid, salicylic acid, p-tercoctylsalicylic acid and sorbic acid; metal salts of divalent or monoesterified carboxylic acids, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, pentane-1,5-dicarboxylic acid, hexane-1,6-dicarboxylic acid, heptane-1 acid ,7-dicarboxylic acid, octane-1,8-dicarboxylic acid, 3,6,9-trioxadecane-1,10-dicarboxylic acid, lactic acid, malonic acid, maleic acid, tartaric acid, oxalic acid, salicylic acid, Italic acid, isophthalic acid, terephthalic acid, hydroxyphthalic acid, and the diesters or triesters of trivalent or tetravalent carboxylic acids, such as hemimelitic acid, trimellitic acid, pyromellitic acid, citric acid, and metal salts of monoesterified or diesterified phosphoric acid or monoesterified phosphorous acid as described in document JP 3275570; and colophonic acids (rosinic acids, such as abietic acid), and superbasic carboxylates.

[0028] The preferred metal soaps in the present invention are metal carboxylates of a carboxylic acid containing between 2 and 25 carbon atoms, usually being acetates, benzoates, or alkanoates, and preferably Csalkanoates, stearates, oleates, laurates, palmitates, behenates , versates, hydroxystearates, dihydroxystearates, p-tert-butylbenzoates, and 2-ethylhexanoates.

[0029] According to the invention, a mixture of carboxylates of different structure can also be used as metallic soaps. Preference is given to the compositions described above containing sodium, zinc and/or calcium soaps.

[0030] Preferably, Zn, Li, K, Mg, Ca, Na salts of the aforementioned fatty acids containing between 2 and 25 carbon atoms are added to the resin or to the composition/product of the invention.

Non-metallic stabilizers

[0031] Among the metal-free stabilizers, mention may be made of p-aminocrotonic acid esters. Among these compounds, for example, p-aminocrotonic acid stearyl ester, 1,4-butanediol-di(p-aminocrotonic acid ester), thio-diethanol-p-aminocrotonic acid ester are considered suitable.

Perchlorates and perfluoroalkanesulfonates

[0032] The polymeric stabilizer composition may also comprise a compound selected from the group consisting of M(ClO ₄ )k and M(CF3SO ₃ )n wherein M is selected from the group consisting of H+, Li+, Na+, K+, Mg2+ , Ca2+, Ba2+, Zn2+, Al3+ and NH4+, and k and k are 1,2 or 3 depending on the valence of M.

[0033] M is preferably selected from the group consisting of Li+, Na+, K+, Mg2+, Ca2+ and Zn2+, more preferably M is selected from the group consisting of Na+, K+ and Ca2+, and even more preferably it is sodium.

[0034] In case of use of a compound of formula M(CF3SO ₃ )n, this is preferably trifluoromethanesulfonic acid or a sodium salt thereof, more preferably sodium trifluoromethanesulfonate.

[0035] For the purposes of the invention, the use of perchloric acid or perchlorate salts is preferred. These can be used in various forms, for example preparations such as aqueous or organic salts or solutions, supported on various materials, such as PVC, calcium silicate, zeolites or hydrotalcites or linked to a hydrotalcite by chemical reaction.

[0036] Furthermore, preferred perchlorates of the invention are complexes of metal perchlorate, more preferably sodium perchlorate, with triethylene glycol, butyl diglycol or polyethylene glycol.

[0037] The composition of the invention may also comprise other additives/excipients capable of behaving as co-stabilizers, selected from the group consisting of antioxidants, organic co-stabilizers (p-diketones and dihydropyridines or polydihydropyridines, uracil derivatives), alkanolamines, zeolites and hydrotalcites. , polyols, hydrates and oxides of alkali and alkaline earth metals and organic phosphites.

Antioxidants

[0038] The organic antioxidants used in the present invention are selected from those already known as additives for plastic materials. For the purposes of the invention, one or more antioxidants selected from the group consisting of alkylidene bisphenols, esters of p-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono or polyalcohols, esters are preferred. of p-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with monoalcohols or polyalcohols, esters of p-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with monoalcohols or polyalcohols. Particularly preferred according to the invention are 2,2'-methylene-bis(6-tert-butyl-4-methylphenol), commercially available as Lowinox® 22 ^m 46 produced by Chemtura, and p-(3) acid esters. ,5-di-tert-butyl-4-hydroxyphenyl)propionic with octadecanol and with pentaerythritol, respectively Arenox® A76 and Arenox® A10, produced by Reagens, and bisphenol A.

[0039] The antioxidants described above, if present, are preferably included in an amount within the range of 0.01 to 1.0 parts by weight, more preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of CPVC.

Organic co-stabilizers

[0040] The invention also contemplates the optional presence of organic co-stabilizers in the composition of the invention to further increase the effectiveness of the stabilizing composition. Organic co-stabilizers optionally present in the stabilizer composition of the invention are preferably one or more compounds selected from dihydropyridines, polydihydropyridines and uracil derivatives.

[0041] Dihydropyridines ( DHP). Preferred monomeric dihydropyridine derivatives for use in the present invention include esters of carboxylic acids according to general formula (II):

where Z is CO2C2H5 or CO ₂ (n-Ci2H25) and R" is hydrogen, C1-C18 alkyl, C2-C18 alkoxycarbonyl or Ca-Cio aryl.

[0042] Particularly preferred is 3-bisdodecyloxycarbonyl-2,a-dimethyl-1,4-dihydropyridine, commercially available as Stavinor® D507 (PMC Group).

[0043] Uracil derivatives. The uracil derivatives advantageously present in the composition of the invention are described by the general formula (III):

where:

R4 and R5 are, independently of each other, hydrogen, C1-C12 alkyl, C3-Ca alkenyl, C5-C ₈ cycloalkyl optionally substituted with between 1 and 3 C1-C4 alkyl, C1-C4 alkoxy, C5-C ₈ cycloalkyl or hydroxyl or with chlorine atoms, or C7-Cg phenylalkyl optionally substituted on the phenol ring with between 1 and 3 C1-C4 alkyl, C1-C4 alkoxy, C5-C ₈ cycloalkyl or hydroxyl or with chlorine atoms; And it can be oxygen or sulfur.

[0044] Examples of C1-C4 alkyl are methyl, ethyl, n-propyl, isopropyl, n-, iso-, sec- or tert-butyl.

[0045] In addition to the aforementioned radicals, examples of C1-C12 alkyl are pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, isooctyl, nonyl, decyl, undecyl, dodecyl. Examples of C1-C4 alkoxy are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy.

[0046] Examples of C5- _C8 cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl. Examples of C7-Cg phenylalkyl are benzoyl, 1-phenylethyl or 2-phenylethyl, 3-phenylpropyl, a,a-dimethylbenzyl, or 2-phenylisopropyl, preferably benzyl. If the cycloalkyl or phenyl groups of the phenylalkyl radical are substituted, then they are substituted with one or two substituents, preferably selected from chloro, hydroxyl, methyl or methoxy.

[0047] Examples of C3-Ca alkenyl are allyl, methallyl, 1-butenyl or 1-hexanyl, preferably allyl.

[0048] Compounds of the formulas indicated above are preferred, in which R4 and R5 are, each independently of each other, C1-C4 alkyl and hydrogen; in particular, the compound in which R4 and R5 are methyl is preferred.

[0049] Among the uracil derivatives, oligomeric or polymeric derivatives according to the formula (III') may also be optionally present in the composition of the invention: (III') where:

A is n-octyl, n-octadecyl, oleyl, phenyl, cyclohexyl or 3-hydroxyphenyl and

B is hexamethylene, 3-methylene-3,5,5,trimethylcidohexan-1-yl, 4,4'-methylene-bis-cidohexyl, 4,4'-methylene-bis-phenyl, X is oxygen, or

if A is phenyl and B is hexamethylene, then X is sulfur;

k ranges from 0 to 17, preferably from 0 to 2. Oligomeric derivatives described above are preferred in the invention.

[0050] The organic co-stabilizers described above may preferably be present in an amount within the range of 0.01 to 1.0 parts by weight, in particular 0.1 to 0.5 parts by weight, per 100 parts by weight of CPVC.

Alkanolamines

[0051] The alkanolamines, advantageously present in the composition of the invention, are compounds according to the general formula (IV):

where

x = 1,2, 3;

y = 1,2, 3, 4, 5 or 6;

n is from 1 to 10

R1 and R2 are independently H, C1-C22 alkyl,

C2-C20 alkenyl, C2-C18 acyl, C4-C ₈ cycloalkyl, which may also be substituted by hydroxyl in the p position, C ₆ -C10 aryl, C7-C10 arylalkyl or alkylaryl, or if x = 1, then R1 and R2 can further combine with nitrogen to form a cycle of 4-10 carbon atoms and optionally up to 2 heteroatoms, or if x = 2, then R1 may additionally be C2-C18 alkylene, which may be substituted with hydroxyl on both carbon atoms in p and/or may be interrupted by one or more NR groups;

Ra3, Rb3 are independently C1-C22 alkyl, C2-C ₆ alkenyl, Ca-C io aryl, H or CH ₂ -X-R5, where X is oxygen, sulfur, -O-CO- or C ^or -O-;

R4 is C1-C18 alkyl, alkenyl or phenyl and

R5 is H, C1-C22 alkyl, C2-C22 alkenyl, or Ca-C1o aryl.

[0052] Preferred trialkanolamines according to general formula (IV) are those in which Ra3, Rb3 are, independently of each other, H or methyl, and y = 1.

[0053] Other alkanolamines are diamines according to the general formula (V):

where:

n is an integer from 3 to 4, x, y, z are independently of each other an integer from 1 to 20, w is an integer from 1 to 2, R1 is a C ₈ -C20 hydrocarbon residue of a compound selected from the group consisting of tallow, cottonseed oil, soybean oil and coconut oil. The diamine (V) of the invention is advantageously N,N',N'-tris(3-hydroxypropyl)-N-coco-alkyl-1,3-propanediamine, N,N,N'-(2-hydroxyethyl)- N'-C12-18-alkyl-1,3-propanediamine, N,N',N'-tris-(2-hydroxyethyl)-N-tallow-alkyl-1,3-propanediamine, N,N',N' -polyoxyethylene(15)-N-tallow-alkyl-1,3-propanediamine, or N,N',N'-tris(2-hydroxyethyl)-N-coco-alkyl-1,3-propanediamine.

[0054] Examples of preferred alkanolamines according to the general formula are: tri(hydroxyethyl)amine, tri(hydroxypropyl)amine.

[0055] The alkanolamines described above may preferably be present in an amount within the range of 0.01 to 1.0 parts by weight, in particular 0.1 to 0.5 parts by weight, per 100 parts by weight of polymer and are preferably used in combination with perchlorates and perfluoroalkanesulfonates.

Hydrotalcites

[0056] The hydrotalcites optionally present in the compositions of the invention can be described by the following general formula:

[M2+1.xM3+x(OH) ₂ ]x+[W'x/nmH ₂ O]x-

where M2+ represents at least one divalent metal cation from the group consisting of Mg, Zn, Ni, Ca; M3+ represents at least one trivalent metal cation from the group consisting of Al, Fe; An- is an anion that has a valency between 1 and 4; x and m represent positive numbers that satisfy the following expressions:

0.2 < x < 0.33 y

m > 0.

[0057] In the above general formula, An represents an anion selected from the group consisting of CO ₃ 2', OH', HCO ₃ ', ClO ₄ ', NO ₃ -, I-, [Fe(CN)a]4 -, acetate, salicylate, tartrate (bivalent) and oxalate (bivalent).

[0058] Preferred hydrotalcites of the invention are those in which An- is selected from CO ₃ 2-, OH-.

[0059] The preferred empirical formulas for hydrotalcite considered for the invention are:

MgaAl2(OH)1aCO ₃ -4H ₂ O

Mg4Al2(OH)12CO ₃ -3H ₂ O

Zeolites

[0060] The zeolites optionally present in the compositions of the invention can be described by the general formula:

Mq/a[(AlO ₂ )q(YES ₂ )r]wH ₂ O

where a is the charge on the cation M,

[0061] M is an element from the group of alkali or alkaline earth metals, in particular Na, K, Mg, q is a number greater than or equal to 2, the ratio q/r is a number greater than or equal to 0.4, being preferably a number between 0.4 and 10.5, and w is a number between 0 and 300.

[0062] Preferred zeolites, optionally present in the composition of the invention, are described in "Atlas of Zeolite Structure Types", WM Meier and DH Olson, Butterworths, 3rd Edition, 1992.

[0063] Zeolites having a particle size mainly within the range of 0.5 to 10 microns are particularly preferred.

[0064] Preferred zeolites, which are known per se, have an average effective cavity diameter of 3-5 A and can be prepared by known methods.

[0065] Also particularly preferred are NaA-type zeolites, which have an average effective cavity diameter of 4 A, and are therefore known as 4A zeolites, indicated by the formula:

Nai2Ali2Sii2O ₄ 8'27H ₂ O.

[0066] Particular preference is given to those zeolites that comply with the general formula indicated above, known as zeolites X and indicated by the formula

(Na ₂ ,Ca,Mg) ₂ gAl58Sii34O384'240H ₂ O.

Polyols

[0067] Among the polyols, optionally present in the composition of the invention, the following are preferred: pentaerythritol, dipentaerythritol, tripentaerythritol, bistrimethylolpropane, bistrimethylolethane, trimethylolpropane, inosite, polyvinyl alcohol, sorbitol, maltite, isomaltite, lactite, lycasin, mannitol, lactose, leucrose, tris(hydroxyethyl)isocyanurate, palatinite, tetramethylolcyclohexanol, tetramethylolcyclopentanol, tetramethylolcyclopyranol, glycerol, diglycerol, polyglycerol, thiodiglycerol or 1-0-aD-glycopyranosyl-D-mannitol dihydrate. Most preferred among the polyols are tris(hydroxyethyl)isocyanurate (THEIC), pentaerythritol, dipentaerythritol, trimethylolpropane, bistrimethylolpropane, sorbitol.

[0068] If present, the polyols are preferably present in an amount within the range of 0.01 to 2 parts by weight, in particular 0.1 to 1 parts by weight, per 100 parts by weight of polymer that contains halogen.

Phosphites

[0069] The phosphites, optionally present in the composition of the invention, are preferably organic phosphites of general formula P (OR) ₃ , in which the R radicals are identical or different and can be C ₆ -C18 alkyl, C ₆ alkenyl -C18, C5-C7 cycloalkyl. Also included as preferred in the invention are acid phosphites of the general formula P(OH)R2, in which the R radicals are identical or different and are selected from C ₆ -C18 alkyl, C ₆ -C18 alkenyl, phenyl, monoalkylphenyl or dialkylphenyl, or C5-C7 cycloalkyl.

[0070] Phosphites with the following general formula may also be present in the composition of the invention:

wherein R1 and R2 are identical or different and are C ₆ -C18 alkyl, C ₆ -C18 alkenyl, phenyl, monoalkylphenyl or dialkylphenyl, or C5-C7 cycloalkyl. Among these latter phosphites, those in which R1, R2 = stearyl or

[0071] Phosphites may also be present with the following general formula:

(R1O) ₂ -PO-R2-OP-(OR3) ₂

where R1 and R3 are identical or different and are Ca-Cm alkyl, C ₆ -C18 alkenyl, phenyl, monoalkylphenyl or dialkylphenMo, or C5-C7 cycloalkyl, R2 is alkyl, alkyloxy, aryl or arylalkyl.

[0072] Each C ₆ -C18 alkyl substituent present is, for example, n-hexyl, n-octyl, n-nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl. Groups having 8 to 18 carbon atoms are preferred.

[0073] Preferred phosphites in the present invention include:

tri(isodecyl)phosphite, tri(nonylphenyl)phosphite, tri(isotridecyl)phosphite, diphenyl isodecyl phosphite, di(isodecyl) phenyl phosphite, di(nonylphenyl) phosphite, tetraphenyl dipropylene glycol diphosphite, 4,4' isopropylidenediphenol tetra(C12-15 alcohol ) phosphite, bis(2,4-di-tbutylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite.

[0074] If present, the phosphites are preferably in an amount within the range of 0.1 to 2 parts by weight, more preferably 0.2 to 0.5 parts by weight, per 100 parts by weight of CPVC .

[0075] In a preferred embodiment of the invention, the stabilizing composition consists of sodium adipate in an amount greater than 0.3 parts by weight per 100 parts of chlorinated polyvinylchloride, and no other stabilizer or co-stabilizer is used. The halogenated resin of the invention can be in a rigid, semi-rigid and plasticizing formulation.

[0076] The halogenated resin may be a plasticizer or semi-rigid formulation comprising chlorinated polyvinylchloride formulated with plasticizer compounds.

[0077] The halogenated resin may be a rigid formulation comprising chlorinated polyvinylchloride and being substantially free of plasticizer compounds.

[0078] The compounds present in the stabilizer composition can be added to the resin formulation by mixing by dry mixing. The resin formulation is then used to prepare final CPVC articles. The final product item can be any type of CPVC product, which needs enhanced thermal stabilization, for example: extruded and injection molded items, rigid and semi-rigid films, sheets, profiles, automotive parts. The articles may be manufactured by any process available to those skilled in the art, including, but not limited to, extrusion, injection molding, compression molding, thermoforming, drip molding.

[0079] In another aspect, the invention relates to the use as defined in claim 7.

[0080] The invention will be detailed below using illustrative and non-limiting examples.

experimental part

Examples 1-7

[0081] All starting materials were commercially available.

Main ingredients:

Chlorinated polyvinyl chloride (CPVC)

disodium adipate

[0082] CPVC was available from Sekisui, Kaneka, Kern One as Sekisui HA-58K, Kaneka H829F, Kern One RB 1167, Kern One RB 8065, Kern One RB 8067, Sekisui HA-24KL.

[0083] Disodium adipate was available from Reagens SpA and had the following particle size per volume density measured by Malvern Metasizer 3000 equipped with Aero S accessory for powder analysis:

[0084] The resin formulation contained the main ingredients and additional ingredients specified above in the amounts, expressed as parts by weight per 100 parts by weight of CPVC (phr), as summarized in the following Table 1:

Table 1: resin formulation (I) according to the invention for Examples 4-7

[0085] The formulations indicated with (C) were comparative (Examples 1, 2 and 3) and contained the same ingredients as Formulation (I) of the invention apart from the amount of disodium adipate, as will be evident from the Table 2 shown below. Formulations (I) and (C) were rolled by roller to obtain sheets of 0.3-0.5 mm, for 3 minutes at 190 °C. Rectangular samples (1.5*24 cm) were cut from each of the sheets. The following tests were used.

Test for the evaluation of thermal stabilization:

[0086] The slides were subjected to heating at 200 ° C in glass tubes according to the known Congo Red test until the color change to red of an indicator paper placed on the top of the tubes due to the evolution of HCl triggered by the degradation of chlorinated resin. According to this rule, the longer the time until color change to red, the better the thermal stabilization. This test, when performed on high-temperature thermoformed samples, was representative of the long-term thermal stabilization of chlorinated polyvinyl chloride processing.

Test for VICAT evaluation:

[0087] The VICAT softening temperature was evaluated according to ISO ₃ 06 in 2 mm compression molded plates of the tested formulations.

[0088] This test, when performed on high temperature thermoformed samples, was representative of the VICAT temperature of chlorinated polyvinyl chloride (CPVC) samples.

Test for fusion evaluation:

[0089] To evaluate fusion, the rheological behavior of formulations (C) and (I) was evaluated.

[0090] Rheology was evaluated with a Brabender PL2100/3 torsion rheometer equipped with a W50EH roller mixer at 190 ° C, 40 rpm and 62 g of sample formulation as in Table 1 for 8 minutes. The fusion time was the time to the maximum torque that indicated the fusion time.

[0091] This test, when carried out at high temperature processing with rotors similar to those of an extruder, was representative of the melting behavior in a chlorinated polyvinyl chloride (CPVC) extruder to which disodium adipate was added.

[0092] The results for resin formulations (I) and (C) are indicated in the following Table 2 together with the amounts of disodium adipate.

[0093] The formulations according to the present invention indicated in Table 2 meet all the desirable characteristics listed below:

- Stability in Congo red > 53 min. This value is the minimum value to obtain a chlorinated resin formulation capable of resisting the processing procedure used industrially;

- VICAT > 82 °C;

- Fusion time < 78 s. This value is the maximum value to obtain a chlorinated resin formulation capable of providing good quality articles.

[0094] Therefore, the formulations of the inventions (I) make it possible to obtain stabilized CPVC formulations with a short melting time also in the absence of tin stabilizers.

Examples 8-9

[0095] Evaluation of disodium adipate with the following different particle size (obtained with a Malvern Metasizer 3000 equipped with an Aero S accessory for powder analysis) was carried out according to the experimental procedures described in examples 1-7:

[0096] The results are indicated in the following table:

[0097] As shown from the previous results, both compositions according to Examples 8 and 9 achieve adequate stability in Congo Red in order to obtain a chlorinated resin formulation capable of resisting the processing procedure used industrially. At the same time, it can be observed that the use of disodium adipate with a finer particle size (example 8) allows obtaining a stabilized CPVC formulation with even greater thermal stability, also in the absence of tin stabilizers, thus demonstrating the relevance of the particle size of the disodium adipate and the preference for a particle size that shows a D90 value of less than 8.0 microns, a D50 value of less than 1.8 microns and a D10 value of less than 0.6 microns.

Examples 10-11

[0098] The evaluation of disodium adipate and disodium succinate with particle size analogous to disodium adipate 1 was carried out according to the experimental procedures described in Examples 1-7.

[0099] The results are indicated in the following table:

[0100] As shown from the results set forth above, in example 10 a stabilized CPVC formulation with greater thermal stability is obtained, also in the absence of tin stabilizers, compared to example 11, where a formulation was used stabilizer based on disodium succinate. This demonstrates the importance of the sodium salt anion in the stabilizing composition.

Claims (7)

1. Halogenated resin comprising chlorinated polyvinyl chloride (CPVC) and a stabilizing composition comprising disodium adipate in an amount greater than 0.3 parts by weight per 100 parts of polymer (phr), where the halogenated resin does not comprise tin stabilizers and where the disodium adipate of the stabilizing composition shows a granulometric distribution by volume density showing a D90 value less than 8.0 microns, a D50 value less than 1.8 microns and a D10 value less than 0.6 microns, measured using a Malvern Metasizer 3000 equipped with Aero S accessory for dust analysis. 2. Halogenated resin according to claim 1, wherein the disodium adipate salt of the stabilizing composition is present in an amount of between 0.35 and 1.6 parts by weight per 100 parts by weight of CPVC. 3. Halogenated resin according to claim 2, wherein the disodium adipate salt of the stabilizing composition is present in an amount equal to 0.9 parts by weight per 100 parts by weight of CPVC. 4. Halogenated resin according to any of claims 1-3, wherein the resin comprises at least one plasticizing compound. 5. Halogenated resin according to any of claims 1-4, further comprising stabilizing and co-stabilizing compounds selected from the group consisting of metal soaps, perchlorates and perfluoroalkanesulfonates, monosodium adipate, antioxidants, alkanolamines, zeolites and hydrotalcites, polyols, organic phosphites , p-aminocrotonic acid esters and organic co-stabilizers, such as dihydropyridines, polydihydropyridines and uracil derivatives. 6. Chlorinated polyvinylchloride article made of the halogenated resin according to any of claims 1-5, wherein the article has a stability in Congo red > 53 min, measured according to the Congo Red test at 200 ° C, a temperature of VICAT softening > 82 °C, Measured according to ISO ₃ 06 on 2 mm compression molded plates, and where the halogenated resin formulation presents a melting time of < 78 s, measured through rheological evaluation using a Brabender PL2100/3 torsion rheometer equipped with a W50EH roller mixing head at 190 °C, 40 rpm. 7. Use of disodium adipate in an amount greater than 0.3 parts by weight per 100 parts of polymer for the stabilizer chlorinated polyvinylchloride (CPV) in the absence of tin stabilizers, where the disodium adipate of the stabilizer composition shows a particle size distribution by volume density showing a D90 value less than 8.0 microns, a D50 value less than 1.8 microns and a D10 value less than 0.6 microns, measured using a Malvern Metasizer 3000 equipped with Aero S accessory for dust analysis.